Multiyear genotype characterization of eastern spruce budworm outbreaking populations from Quebec and adjacent regions.

Population outbreaks are characterized by irruptive changes in population density and connectivity resulting in rapid demographic and spatial expansion, often at the landscape scale. Outbreaks are common across multiple taxa, many of which inhabit northern ecosystems. Outbreaks of Lepidopteran defoliators in forest ecosystems are a particularly compelling example of this phenomenon, given the massive spatial scales over which these outbreaks can occur, their frequency, and socioeconomic impacts.

Spatial patterns of hyperparasitism along a latitudinal gradient of forest genus diversity: insights from the spruce budworm-parasitoids community.

High-order mobile predators are generally thought to increase ecosystem stability and resilience to natural perturbations. In many insect food-webs, higher trophic positions are occupied by parasitoids, which are themselves hosts for hyperparasitoids that can reduce primary parasitoids' efficiency in controlling insect pests. Hyperparasitoids can thus provide ecosystem disservices by facilitating pest outbreaks, or ecosystem services by stabilizing food web fluctuations over longer time periods.

Landscape-scale population connectivity in two parasitoid species associated with the spruce budworm: Testing the birdfeeder effect using genetic data.

Periodic and spatially synchronous outbreaks of insect pests have dramatic consequences for boreal and sub-boreal forests. Within these multitrophic systems, parasitoids can be stabilizing agents by dispersing toward patches containing higher host density (the so-called birdfeeder effect). However, we know little about the dispersal abilities of parasitoids in continuous forested landscapes, limiting our understanding of the spatiotemporal dynamics of host-parasitoid systems, and constraining our ability to predict forest resilience in the context of global changes.

Temporal variation in spatial genetic structure during population outbreaks: Distinguishing among different potential drivers of spatial synchrony.

Spatial synchrony is a common characteristic of spatio-temporal population dynamics across many taxa. While it is known that both dispersal and spatially autocorrelated environmental variation (i.e.

Perceptions of U.S. and Canadian maple syrup producers toward climate change, its impacts, and potential adaptation measures.

The production of maple syrup is an important cultural and economic activity directly related to the climate of northeastern North America. As a result, there are signs that climate change could have negative impacts on maple syrup production in the next decades, particularly for regions located at the southern margins of the sugar maple (Acer saccharum Marsh.) range.

Parasitism Rates of Spruce Budworm Larvae: Testing the Enemy Hypothesis Along a Gradient of Forest Diversity Measured at Different Spatial Scales.

Vegetational diversity is generally thought to be associated with ecosystem stability and resilience to perturbations such as insect outbreaks. The enemies' hypothesis states that vegetational diversity contributes to greater top-down control of insect pests, by providing further resources to natural enemies than homogeneous environments. However, direct evaluation of this hypothesis is difficult because different species of natural enemies can respond to vegetational diversity in dissimilar manners and at different spatial scales depending on functional traits such as prey/host specificity and dispersal.

Seasonal ecology and thermal constraints of Telenomus spp. (Hymenoptera: Scelionidae), egg parasitoids of the hemlock looper (Lepidoptera: Geometridae).

We describe seasonal patterns of parasitism by Telenomus coloradensis Crawford, Telenomus droozi Muesebeck, Telenomus flavotibiae Pelletier (Hymenoptera: Scelionidae), and Trichogramma spp. (Hymenoptera: Trichogrammatidae), egg parasitoids of the hemlock looper, Lambdina fiscellaria (Guenée) (Lepidoptera: Geometridae), after a 3-yr survey of defoliated stands in the lower St. Lawrence region (Quebec, Canada).